Automatic Reading of ANCA-Slides: Evaluation of the AKLIDES System

• Main Authors: Jan Damoiseaux, Kathleen Mallet, Mia Vaessen, Jos Austen, Jan Willem Cohen Tervaert
• Format: Article
• Language: English
• Published: Hindawi Limited 2012-01-01
• Series: Clinical and Developmental Immunology
• Online Access: http://dx.doi.org/10.1155/2012/762874
• ISSN: 1740-2522; 1740-2530

The ANCA consensus prescribes screening by indirect immunofluorescence on neutrophils. We evaluated the first automated ANCA-pattern recognition system. C-ANCA and P-ANCA samples were selected from patients with ANCA-associated vasculitis (AAV). Non-AAV controls included sera from healthy controls , sera with possible interfering antibodies , or miscellaneous ANCA reactivity . ANCA slides were analysed by AKLIDES and routine fluorescence microscopy. The C-ANCA pattern was recognized by routine microscopy in 92% and 97% on ethanol- and formalin-fixed slides, respectively. AKLIDES reported C-ANCA in 74% and 95%, respectively. P-ANCA was recognized by routine microscopy on ethanol-fixed neutrophils in 90%, while AKLIDES reported P-ANCA in 80%. Typically, only 65% and 33% of these samples showed the expected C-ANCA on formalin-fixed neutrophils by routine microscopy and AKLIDES, respectively. A C- or P-ANCA pattern was observed on ethanol-fixed neutrophils in 28% and 23% of the controls by routine microscopy and AKLIDES, respectively. Only 5% of the controls revealed C-ANCA on formalin-fixed neutrophils by routine microscopy and AKLIDES. Altogether, automated ANCA-pattern recognition by AKLIDES is promising. Distinction of C- and P-ANCA is good, but sensitivity on ethanol-fixed neutrophils needs improvement. When optimized, pattern recognition software may play an important role in AAV diagnostics.